Improvement in devices for shaping piano-keys



M. PRATT.

lDevine for Sh`ap'ng Piano-Keys.

Patent,ed'Aprl20,1875.

/if my UNTTED STATES PATENT OFFICE.

MILON PRATT, OF DEEP RIVER, CONNECTICUT, ASSIGNOR TO PRATT, READ & CO., OF SAME PLACE.

IMPROVEMENT IN DEVICES FOR SHAPING PIANO-KEYS.

Specification forming part of Letters Patent No. 162,4 [7, dated April 20, 1875 application filed March 9, 1875.

To all whom 'it may concern:

Be it known that I, MILoN PRATT, of Deep River, in the county of Middlesex and Sta-te of Connecticut, have invented a new Device for Shaping Piano-Keys; and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters ot' reference marked thereon, to be a i'ull, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in

Figure l, front view 5 Fig. 2, top or plan; Fig. 3, end view; Figs. 4, 5, and 6, detached views Fig. 7, perspective view of a finished key.

Ilhis invention relates to an apparatus for holding and presenting to a revolving' cutter the blanks for flats and sharps of pianos and similar musical instruments with special ret'- erence to the class of flats and sharps known to the trade as Grecian Bend-that is to say, the surface at the rear or inner end curved downward, as seen in Fig. 6. The object ot the invention is to hold and present the blank to a revolving cutter, so that the surface will be dressed to this shape.

A is the bed, which is stationary; B, the cutter, 011 a vertical shaft, substantially the same as the cutter of other dressing or shaping machines. The bed is constructed with suitable guides C, to receive the carriage D and allow it to be moved' longitudinally back and forth. 0n this carriage D the clamp or Yholder is hung upon a pivot, E. This clamp consists ot' a pair of jaws, F I, the one F hinged to the other, I, as seen in Fig. 3, and a thumb-screw, L, through one part into the other serves to separate or close the jaws. The edge of -the jaws is shaped substantially like the surface ot` the key to be produced, as seen in Fig. 2, and between the jaws the blank His clamped, as seen in Figs. l and 2. 011 the under side ot` the carriage D a lever or latch, P, is hung, as seen in Fig. 5a part ot' the carriage removed to show it. One end, c, of this lever is turned up through a slot, d,

vin the carriage, so that the clamp will bear against said end a, as seen in Fig. 2. At the other end the clamp is prevented from turning by a stationary stop, e; hence the clamp and carriage will be moved together, presenting the blank to the cutter to be dressed. To turn the clamp, as the rear end approaches the cutter the latch or hook R of the lever P strikes a stop, r, on the bed just as that point Where the curve commences has reached the cutter. This will positively arrest the further advance of the carriage. As .the hook R reaches the stop r an incline, n, on the lever first strikes the stud r. This causes the lever to be turned, as denoted in broken lines, Figs. 4 and 5. This brings the end a of the lever before a slot, m, in the lower part of the clamp; hence, so soon as the carriage stops, the clamp is free from the end a ot' the lever. The operator then presses forward against the clamp, causing it to turn upon its pivot E, as denoted in broken lines, Fig. 2, and the last or rear end ot the blank to pass the cutter in a circular path, of which the pivot E is the center, and the blank will be dressed on such curve. After the blank'` has been thus dressed the clamp is drawn back against the stop c, and then the carriage returned for a second operation.

This device, including the bed A, may be made as an attachment for machines which have a suitablecutter, and removable therefrom when not required for use, or the bed may be a stationary part of the machine.

I claim- 1. The combination ot' the reciprocating carriage D and pivoted clamp F I, substantially as and for the purpose described.

2. The combination of the bed A, reciproeating carriage D, pivoted clamp F I, and lever P, constructed and operating substantially as described. j

MILON PRATT.

Witnesses:

FELIX A. DENIsoN, S. M. SHIPMAN. 

